By Debra Colodner PhD, Director of Conservation Education and Science at the Arizona-Sonora Desert Museum and Ruth Allard, Senior Vice President of Conservation and Education at the Phoenix Zoo

Plans for additional primary and secondary border wall and related construction are accelerating rapidly in southern Arizona. While we appreciate the need for border security, wildlife conservation organizations including the Arizona-Sonora Desert Museum and the Phoenix Zoo are concerned about the environmental and cultural impacts of these projects. Physical impediments to wildlife movement alter connectivity in critical habitat for jaguar, ocelot, Mexican grey wolf and other species whose native ranges extend through the borderlands region. Proposed additional and secondary wall construction threatens the last remaining home for multiple species of conservation concern. This region is important ecologically as well as culturally, home to people, plants and animals for whom these changes will be devastating. We strongly urge decision-makers to halt these plans. 

Researchers at the University of Arizona’s Wild Cat Research and Conservation Center, Sky Island Alliance, Phoenix Zoo, Center for Biological Diversity, and Wildlands Network, among others, have been documenting the impact of the border wall on wildlife movement. In a 2022-24 study, they found that only 9% of the animals who encountered the new wall structures successfully crossed. Small wildlife openings in border walls (8.5 inches wide and 11 inches tall) facilitated 16.7 times more movement for some animals like the javelina, mountain lion, and coyote, but more frequent and larger openings are urgently needed.

Construction of additional wall has already begun in the Pajarito Mountains, part of the Atascosa Complex where the Phoenix Zoo has led a wildlife camera study observing 50+ animal species since 2023, including the first ocelot recorded west of I-19 in over 50 years. Black bears, jaguars, adult mountain lions, Mexican wolves and other wildlife depend on habitat connectivity to find shelter, food and water and to find mates and raise their young. This new construction will further limit movement in a critical wildlife corridor, bisect a US-designated Wilderness area and isolate animals from essential resources and from each other.

In Arizona’s Organ Pipe Cactus National Monument, just 200+ feet from the existing border wall, and potentially in the path of a planned secondary border wall and affiliated infrastructure, Quitobaquito Pond and the associated Quitobaquito Springs and spring channel is home to three incredibly imperiled wildlife species. This desert oasis on National Park Service land is the only place on Earth that the endangered Quitobaquito pupfish and the proposed-endangered Quitobaquito tryonia springsnail remain in the wild. The endangered Sonoyta mud turtle is found nowhere else in the wild in the United States and a good portion of its critical habitat stands in the path of a potential secondary border wall. The Desert Museum houses a backup population of the mud turtles, and was the first institution to successfully breed them in captivity. We have plans to host a population of pupfish as well, as needed by Federal and State agencies. Our partners at the Phoenix Zoo host a population of the springsnails. With environmental regulations waived for the secondary border wall, all three of these highly vulnerable species are at risk of losing their habitat forever.

Where additional border wall construction is determined to be unavoidable, we encourage border wall design and management recommendations aimed at allowing animals to cross, securing connectivity for wildlife populations. At Quitobaquito Pond and other areas of critical habitat for US endangered species and of significant cultural importance, we strongly advocate for nondestructive technological solutions such as those already planned in the border region.  

Ultimately, the construction of any additional border walls in these unique and fragile landscapes risks creating irreversible consequences for species already imperiled.